scratchfoundation/paper.js
1
0
Fork 0
mirror of https://github.com/scratchfoundation/paper.js.git synced 2025-01-07 13:22:07 -05:00
Code Issues Projects Releases Packages Wiki Activity Actions

Revert "Change the way we determine the winding in getWinding()."

Browse source
This commit is contained in:
Jürg Lehni 2016-02-03 17:46:27 +01:00
parent 0152439627
commit f7b1aca3e4
1 changed files with 21 additions and 25 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

46
src/path/PathItem.Boolean.js
View file

@ -314,7 +314,6 @@ PathItem.inject(new function() {
py = point.y, py = point.y,
windLeft = 0, windLeft = 0,
windRight = 0, windRight = 0,
isOnCurve = false,
length = curves.length, length = curves.length,
roots = [], roots = [],
abs = Math.abs; abs = Math.abs;
@ -357,12 +356,13 @@ PathItem.inject(new function() {
values = curve.values, values = curve.values,
yStart = values[1], yStart = values[1],
yEnd = values[7]; yEnd = values[7];
// The first curve of a loop holds the last curve with non-zero // The first curve of a loop holds the last curve with
// winding. Retrieve and use it here (See _getMonoCurve()). // non-zero winding.
// Retrieve and use it here (See _getMonoCurve()).
if (curve.last) { if (curve.last) {
// Get the end x coordinate and winding of the last // Get the values of to the end x coordinate and winding of
// non-horizontal curve, which will be the previous // the last non-horizontal curve, which will be the previous
// non-horizontal curve for first curve in the loop. // non-horizontal curve for the first curve of the loop.
prevWinding = curve.last.winding; prevWinding = curve.last.winding;
prevXEnd = curve.last.values[6]; prevXEnd = curve.last.values[6];
} }
@ -381,25 +381,25 @@ PathItem.inject(new function() {
? Curve.getPoint(values, roots[0]).x ? Curve.getPoint(values, roots[0]).x
: null; : null;
if (x != null) { if (x != null) {
// If the point is between the curve's start point and
// the previous curve's end point, it must be on a
// horizontal curve in between.
var isOnHorizontal =
py === yStart && (px - x) * (px - prevXEnd) < 0;
// Test if the point is on a y-monotonic curve
if ((x >= xBefore && x <= xAfter) || isOnHorizontal)
isOnCurve = true;
// Count the intersection of the ray with the // Count the intersection of the ray with the
// y-monotonic curve if: // monotonic curve if:
// - the crossing is not the start or end of the curve // - the crossing is not at the start of the curve
// - or the crossing is at the start of the curve and // - or the windings are opposite (intersect at a
// the winding did not change between curves // vertical extremum)
if (py != yEnd // - or the start of the current curve and the end
&& (py != yStart || winding === prevWinding)) { // of the prev curve are on opposite sides of px
var isWindingChange = winding === -prevWinding;
if (py !== yStart || isWindingChange
|| (x - px) * (prevXEnd - px) < 0) {
if (x < xBefore) { if (x < xBefore) {
windLeft += winding; windLeft += winding;
} else if (x > xAfter) { } else if (x > xAfter) {
windRight += winding; windRight += winding;
} else if (py === yStart && isWindingChange) {
// The point is a vertical extremum of the
// path.
++windLeft;
++windRight;
} }
} }
} }
@ -410,11 +410,7 @@ PathItem.inject(new function() {
} }
} }
} }
// If the point is on a monotonic curve, ensure that the winding is odd return Math.max(abs(windLeft), abs(windRight));
// by applying bit-wise or `| 1` to the bigger absolute winding number:
// If winding is an even number and the point is on a curve, this will
// add up to the next uneven number, otherwise it remains the same.
return Math.max(abs(windLeft), abs(windRight)) | (isOnCurve ? 1 : 0 );
} }
function propagateWinding(segment, path1, path2, monoCurves, operator) { function propagateWinding(segment, path1, path2, monoCurves, operator) {